According to the excerpt given from Flannery O'Connor's "The Life You Save May Be Your Own.", there is a monologue where the narrator compares the human body to a house because it doesn't go anywhere.
The second simile comes when the narrator compares the spirit to an automobile because it is always on the move.
Therefore, the excerpt contains two similes.
P. S A simile is a figure of speech that compares two dissimilar things using 'like' or 'as'
From my understanding all you are doing is converting liters to grams. It says you have one leader of hydrogen peroxide. 1 liter equals 1000 grams. And if it is asking how many grams are in 1 liter hydrogen peroxide then the answer would be 1000 grams